204 



COMPARATIVE ANATOMY 



CHAP. 



runs along the thickened edge of the mantle which concresces with the nuchal integu- 

 ment. From this vein spring numerous venous vessels which spread out on the 



FK,. 1 7 o. Pulmonary veins, heart, and arterial system of Helix (after Howes). The mantle 

 (roof of pulmonary cavity) is cut open ami turned bark. 1, Pulmonary vein (efferent pulmonary 

 vessel); L', kidney; 3, auricle; -1, ventricle ; ."., rectum, cut through; '>, hermaphrodite ghmd ; 

 7. columellar muscle ; S. aorta viseeralis ; '., salivary glands : ](. aorta cephalica. 



under surface of the mantle. /.,. on the roof of the mantle cavity, and there form a 

 respiratory network. In this network the Mood becomes arterial, and is 



Fn:. 171. -Vascular system of Limax. after drawings combined by Leuckart from Delle Ghiaje 

 and Simroth. Tlie veins carrying the venous blood out of the body into the lungs are black. 

 A, auricle ; V, ventricle ; VR, venous circular sinus of the pulmonary cavity ; Ax, aorta cephalica ; 

 Ay, aorta visceralis ; M, muscular stomach ; ZD, hermaphrodite gland ; //, digestive gland ; /, in- 

 testine ; Al., respiratory aperture ; A", arteria genitalis. 



next conducted through many vessels into the large pulmonary vein (vena pulmon- 

 aris), which runs back almost parallel to the rectum along the roof of the mantle 



